1. Field of the Invention
This invention generally relates to an apparatus for using data such as reproducing or copying the data. This invention particularly relates to a data using apparatus capable of limiting the use of data, for example, forbidding the reproduction or the copying thereof.
2. Description of the Related Art
Data recorded on a package medium such as a CD or a DVD is used in various ways including the following ones. Data is copied from a package medium onto a recording medium within a hard disc drive (HDD) in a personal computer. Data is copied from a package medium onto a recording medium in a recording and reproducing apparatus via a personal computer. Data is directly copied from a package medium onto a recording medium in a recording and reproducing apparatus.
Data can be copied onto or downloaded to a recording medium within a hard disc drive (HDD) in a personal computer through a communication network such as the Internet.
In some cases, the copying of data is for personal use. The transmission of data among machines of many unspecified persons involves the copying of the data beyond personal use. It is difficult to discriminate between the copying of data for personal use and the copying of data beyond personal use. This difficulty sometimes causes a problem associated with the protection of a copyright on the contents of data.
There is an information delivery service for supplying encrypted data which can be used only by specified reproducing apparatuses. Since only specified reproducing apparatuses can use the encrypted data, the information delivery service tends to be inconvenient for a user having a plurality of reproducing apparatuses.
It is known to count the number of times of the copying of data, and forbid the copying of the data when the counted number reaches a prescribed number. It is also known to forbid making a second-generation copy of data. These copy protection technologies are not always in harmony with the range of personal use.
There is a copy protection system designed so that data is erased from a recording apparatus after the data is copied therefrom onto a reproducing apparatus. The copy protection system tends to be inconvenient for a user having a plurality of reproducing apparatuses.
Japanese patent application publication number P2004-110816A discloses a contents copy management system including a contents reproducing apparatus and a contents copy management apparatus. The contents reproducing apparatus sends a management request to the contents copy management apparatus. In response to the management request, the contents copy management apparatus returns either an allowance or a rejection to the contents reproducing apparatus. The allowance enables the contents reproducing apparatus to copy contents. The rejection inhibits the contents reproducing apparatus from copying the contents. The contents copy management apparatus stores a copy permission residual number deciding which of an allowance and a rejection should be returned. The copy permission residual number is decremented each time an allowance is returned.
The contents copy management by the system of Japanese application P2004-110816A can not be applied to a contents reproducing apparatus incapable of communicating with the contents copy management apparatus.
Japanese patent application publication number P2004-120736A discloses a group formation management system including a group management device and member devices registered in a related group. Each of the registered member devices holds common secret information peculiar to the group. The group management device also holds the common secret information. A new device sends a registration request to the group management device. In response to the registration request, the group management device operates as follows. When the number of the registered member devices is less than a limit number, the group management device registers the new device in the group as a new member. Then, the group management device outputs the common secret information to the new registered member device. The new registered member device stores the common secret information. On the other hand, when the number of the registered member devices is not less than the limit number, the group management device does not register the new device in the group. The group management device stores contents. In the case where a member device requests the contents, the group management device authenticates the member device by comparing the common secret information in the group management device and the common secret information in the member device. When the result of the authentication is positive, the group management device outputs the contents to the member device. On the other hand, when the authentication result is negative, the group management device does not output the contents.
The limit number of the registered member devices in the group in the system of Japanese application P2004-120736A is not always in harmony with the range of personal use.